DESCRIPTION (Adapted from the application) The basic study model for this program is primary cultured hepatocytes. The role of the Cell Isolation/Transgenic Core is to provide freshly isolated rat and mouse hepatocytes and mitochondria to program investigators. The Core will: 1. isolate and distribute hepatocytes and mitochondria from Sprague Dawley rats. 2. Isolate and distribute hepatocytes from various transgenic mice and the corresponding wild type mice. 3. House and maintain rats and transgenic mice, including knockout mice for iNOS, GD3 synthase, Bid and Bax, transgenic mice overexpressing Bcl-2 and Bcl-x, and corresponding wild-type strains. Core personnel are well trained and experienced in isolating and culturing primary hepatocytes and preparing mitochondria by homogenization and differential centrifugation. Core staff will also provide consultation on these preparations for all project investigators to meet their specific needs.